User talk:Volunteer Marek/Archives/2010/May

The "other" elasticity article, "Elasticity (economics)"
Just for your possible amusement this weekend -- I ran across the following gem in the "other" elasticity article, "Elasticity (economics)," this p.m.

There are two linear demand curves for which the slope and elasticity are identical.[19] The slope and coefficient of elasticity of a perfectly inelastic demand curve is zero. The slope and coefficient of elasticity for a perfectly inelastic demand curve equal negative infinity. The elasticity is constant along each curve.[19]

I nearly choked on my tea! It's utterly and completely wrong, of course. The slope and elasticity are both constant for those 2 classes of curves, but not identical! The footnotes are to Binger & Hoffman, which I recall as being a pretty good text. I can't imagine they would've made such a sophomoric error (or that no one in the army of grad students they had proofreading the manuscript, and maybe even teaching out of it, didn't catch it). Whoever wrote that section/paragraph in the article must've misread or misinterpreted something.

My first reaction was that slope and elasticity could never be equal, because a component of elasticity is the inverse of the slope. But after a little back-of-the-envelope algebra (literally!), I found that they could be equal under 1 condition, after all: if P = Q×(∆P/∆Q)2, or the inverse function for Q.  (I think my algebra is correct. I just set the (P/Q)×(∆Q/∆P) form of the PED equation equal to the slope (∆P/∆Q) and solved for P or Q.)

That article has a lot of material in it (maybe too much), but it badly needs some major editing. I wasted way too much time this p.m. editing various parts it, and I didn't even begin to scratch the surface. Jarry once mentioned that article as an egregious example of how much duplication there is among many of the articles on demand, supply, and related topics when I expressed concernt about all the redundancy. What a waste of effort, and how potentially confusing for users, since the articles frequently contradict each other. Have you noticed how many "real" economists have signed up for Jarry's Census? With enough help, maybe we could eliminate a lot of that duplication ... over the very, very long run.

Have a nice weekend. The spring weather here is absolutely splendid. --Jackftwist (talk) 22:34, 30 April 2010 (UTC)


 * Yes, at the very least the sentence in the article is missing the word "inverse". I took a look at that article and (like many others) it needs a lot of work. Actually, I think that article should just introduce the general concept of elasticity as %d in x due to %d in y and then serve as a disambig page to various sub articles on particular common elasticities (PED, PES, elasticity of substitution, etc.) and the empirical interpretation of an elasticity as the estimated coefficient in a linear regression where both the dependent and the independent variables are in logs. Have a nice weekend too, it's clearing up around here.radek (talk) 01:57, 1 May 2010 (UTC)


 * I was thinking along the same lines about how the coverage of elasticity could be organized better -- an introductory/overview article for disambiguation, with links to related sub-articles. That would also have the advantage of making each article shorter and more focused.  The same goes for various other topics related to demand & supply.  But as I said, it would have to be a long-run project (either that, or an experienced econ editor would have to devote several weeks to the task!).  And, of course, in the long run, we're all ... --Jackftwist (talk) 23:04, 1 May 2010 (UTC)


 * Yes that's a general problem in trying to fix up economics articles. Some of them are of such low quality that when I look at them I think "it will take weeks and a concerted effort to get this up to par" and then give up. However, I think currently we're in a cyclical boom in terms of interest and motivation with the project so it might be time to "make hay while the sun is shining" and tackle some of these issues. I will try to do some work on the elasticity page(s) along the lines you describe over the next week or so if I can find some time.radek (talk) 23:14, 1 May 2010 (UTC)

Block
You've been blocked for 12 hours for violation of a topic ban as noted here.--Tznkai (talk) 00:55, 1 May 2010 (UTC)